Table 2. --Area of potential spawning grounds, numbers of spawners in escapements, and numbers of 

 smolts produced by each brood year for lakes of the Naknek River system, 19S9-63. 



Lake or basin 



Surface 

 area 



Got, 2 ) 



Area of 



potential 



spawning 



grounds (ha) 



Area per unit 

 lake area 

 (ha/km 2 ) 



Spawners in escapement (thousands) 

 1959 1960 1961 1962 1963 



Coville Lake 

 Grosvenor Lake 

 Iliuk Arm 

 South Bay 

 West End 

 North Arm 

 Northwest Basin 

 Brooks Lake 

 System total 6 

 Total smolts 

 produced 6 by 

 brood year 

 (millions) 



JO. 



73. 



93. 



74. 

 218. 

 181. 



40. 



74. 



790.; 



111.0 



!29.6 



34.5 



3 5.5 



147.8 



7.5 



0.7 



18.0 



55T7T 



0.40 

 0.57 

 0.07 

 0.68 

 0.04 

 0.02 

 0.24 



1,000 



ISO 

 22 

 10 



218 



40 



12 



85 

 2 35 



4 72 

 ( 4 ) 75 

 6 8 



0.45 



!, 251.8 



80 



54 

 200 



'10 



52S.4 551.1 725.1 905.4 



13.0 16.7 11.1 12.1 20.8 



1 Includes Hardscrabble Creek; does not include beach spawning areas. 



2 Hardscrabble Creek weir count. 



3 Includes Brooks River, which commonly has three w-aves of spawning activity. 



^Salmon were observed spawning in the West tnd in 1961, but the number is not known. 



5 Field Reports, 1962 and 1965, Brooks Lake Field Station, Natl. Mar. Fish. Serv. Auke Bay 

 Fish. Lab., Auke Bay, AK 99821. 



6 Stewart, Donald M. (editor). 1969. 1967 Bristol Bay red salmon smolt studies, Appendix 

 D, Table 2, p. 64. Alaska Uep. Fish Game, Inform. Leafl. 154. 



METHODS AND EQUIPMENT 



Sampling Units 



For sampling, the lakes were divided into units, 

 generally on the basis of surface area. Each unit was 

 designated by a system of letters and numbers (N-l, 

 N-2, C-l, C-2, etc.— Fig. 1). Coville Lake was further 

 divided in 1963 and 1964, and the designations of the 

 sampling units were changed (see Fig. 2). The original 

 objectives were to establish units of about equal size 

 that were small enough to reveal possible gradients in 

 biological attributes and few enough to permit sam- 

 pling with a limited effort. As the study progressed 

 some units were further divided and others combined. 



Types of Gear 



Several types of gear were used to sample fish and 

 many revisions were made throughout the 4 yr of the 

 study. 



Pelagic areas were sampled with tow nets similar to 

 those used by Johnson (1956) and Burgner ( 1958). Two 

 types of tow nets were used. The first, which was used 

 in all 4 yr, had a round metal hoop 3 m (10 ft) in 

 diameter with an attached cone-shaped mesh bag 

 about 7.6 m (25 ft) long. It was connected to two boats 

 by bridles and steel cables retrieved by a gasoline- 

 powered winch (1961 and 1962) or by ropes retrieved 

 by hand (1963 [in part] and 1964). The second net. 



which was used only for some collecting in 1964, had a 

 2.7-m-square (9 ft) opening and was towed by ropes 

 and retrieved by hand. 



Tow netting was usually done between 2200 and 

 0200, or in general from sunset to sunrise. Two kinds 

 of tows were made: (1) surface tows (0 to 3 m) with the 

 center of the net 1.4 or 1.5 m from the surface; and (2) 

 deep tows (3 to 6 m) with the center of the net 4.1 or 

 4.5 m from the surface. To produce a "standard" tow, 

 the net was pulled through the water over a 457 m 

 ( 1 ,500 ft) course in about 6 min 15 sec for a surface tow 

 and 6 min 45 sec for a deep tow. Most tows were of the 

 surface type in 1961, but in 1962, 1963, and 1964, a 

 sequence of tows — one surface, two deep, and one 

 surface — was used. 



Field crews selected the specific track to be towed 

 on any night within an area; the general objective was 

 to tow near the middle of a sampling area. When one 

 considers that the crews depended on outlines of hills 

 and mountains and running time for orientation, the 

 selection of specific sampling tracks must be con- 

 sidered as random, with bias toward the center of the 

 sampling area. 



Littoral areas were sampled with beach seines, gen- 

 erally in water less than 3 m deep. Two types of nylon 

 seines were used. One was 31 m (100 ft) long; the 

 center 6 m was 1 m high and had four meshes per inch 

 (2.5 cm), and the balance was 1.2 m high and had two 



